The handling of fluids such as sea water, tailings, acids and others has generated a series of difficulties in mining operations in their various processes, accentuated by the geographical diversity present in the country; microclimates, high altitudes, thermal oscillations, dust in suspension, etc. All these variables contribute to the fluids different elements and compounds such as lime, chlorides, salts and others that force the development of new technologies and the use of special metallurgies, coatings or surface treatments to the equipment exposed to these conditions.
When large differences in fluid levels are continuously generated in the processes of mine water evacuation, leaching, water recovery, among others, and all in the same mining site, in these cases the pumping equipment is exposed to the maximum limits, both mechanical and hydraulic operation, exceeding the maximum suction and/or discharge capacities of the pump (parameter measured through the available NPSH), requiring complex installations that hinder the operation and lead to a shorter useful life of the equipment.
We have solved these problems with our robustly designed VCB Series, available in a wide range of conventional and special metallic materials, diversity of accessories according to the different processes or requirement.
If we analyze in detail the different processes mentioned and the impact of our innovative solution, the dimension of the improvement in the operation becomes unquestionable.
Below, we detail the different processes and the impact of the solutions implemented to manage the variability of fluid levels:
Pumping of Leach Solutions from ILS, PLS and Refining Pools
Leaching is a process that allows copper to be obtained from oxidized minerals containing copper by applying a solution of sulfuric acid and water. This process is based on the fact that oxidized minerals are sensitive to attack by acid solutions. The solution is transformed into PLS and is conducted to collection pools, it is at this point where the management of the constant fluctuation of the fluid level becomes relevant.
Until a few years ago, the prevailing alternative was to pump these fluids from the pools to the electrowinning plant by means of horizontal or vertical centrifugal turbine pumps, continuously exposing the equipment to dry work, sludge and suspended solids, complicating the solvent extraction process, mainly due to the absence of a technology that would allow an efficient and safe operation. On the other hand, the installation of horizontal or vertical centrifugal turbine pumps requires a high investment in civil works to ensure the conditions demanded by these types of pumps for their correct installation.
Today, with our VCB series, in addition to not requiring civil works for its installation, it provides extended periods of maintenance-free operation, providing the pump with a high standard of safety and continuity of operation that can last up to a year without requiring intervention, stopping or disassembling the equipment, an unprecedented situation and also a great achievement in equipment subjected to these demands.
Mine Bottom Water Recovery
Another relevant process is the evacuation of the fluid that accumulates at the bottom of open-pit mining sites, either due to thaws, rains or the drilling of confined aquifers typical of the exploitation of subway galleries.
This problem was also addressed until a few years ago with submersible pumps or portable horizontal pumps. In both cases, the solution brings with it other problems, such as constant failures in the submersible equipment due to severe wear and tear, the large amount of spare parts and labor required for repairs, and significant equipment downtime.
Our VCB series always sucks from the top, avoiding the direct pumping of the material from the bottom of the mine, this added to the different alloys with which the pump can be manufactured, increases considerably its useful life. It can work dry without damage, and does not require civil works for its assembly. In addition, if the work is at a considerable height above sea level (more than 2,000 meters above sea level), the suction conditions become critical, so that, with the use of this type of equipment, the NPSH problem is avoided, and in the event of changes in extraction levels, the system considers floating pumps controlled by frequency variators, which allows 100% flexibility in the modulation of the system.
Water recovery in Tailings Tanks
The process of water recovery in tailings dams is a great opportunity for mining companies to reuse the water resource. The high concentration of solids in the tailings, the presence of multiple complex compounds, large extensions of the dams and a bottom saturated with mineral pulp make it difficult to pump these fluids and therefore, very restricted the range of solutions and very relative successes, so again, we are facing a problem well solved through our floating cantilever type equipment that pump from the dam to ponds the liquid that has already precipitated a significant amount of solids thanks to the decantation.